Who says it was "shot illegally" ?? Did not know there were any restrictions on photography aboard Ryanair A/c.
The laws in most jurisdictions says.
It is generally illegal to film or record on private property without permission. I cannot look it up now but I know it is in the terms of carriage for at least three international airlines and is written clearly in their in flight magazine with other "fine print". You agree to their terms and conditions when you purchase a ticket.
An aircraft is not deemed "a public place", it is private property, just like a shopping centre. Many people mistakenly believe this is "public" and therefor they can record video but that is not the case.
However it is a moot point.